H/sup -/ production in a multicusp microwave plasma

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:7012250

Trow, J R

High energy neutral beams are necessary for the continued development of magnetically confined fusion plasma devices. Neutral beams based on positive ions are not efficient at beam energies of 100 keV or above; however, negative ion based neutral beam systems are efficient, even at high beam energies. Volume production of H/sup -/ has many advantages over the other methods, chiefly: simplicity of design and operation, and no need for alkali metals. Since volume production requires a low electron temperature, but also requires molecular intermediates only formed by more energetic electrons (>20 eV), double plasma devices with a separate hot electron region are desirable. Therefore, an experiment was undertaken to examine H/sup -/ production by volume processes in a multicusp microwave discharge, part of the cusp field being enhanced to produce an ECR (electron cyclotron resonance), that would also isolate the hotter plasma formed there. This arrangement is analogous to the magnetic filters used in some other negative ion sources. This work describes the experiment setup and the results obtained, which are a survey of the behavior of this type of device. Also included is a discussion of the volume processes associated with H/sup -/ production, including numerical estimates, based on the experimental measurements.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 7012250
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700205* -- Fusion Power Plant Technology-- Fuel
Heating
& Injection Systems
BEAM INJECTION
BEAMS
CUSPED GEOMETRIES
CYCLOTRON RESONANCE
ELECTRIC DISCHARGES
ELECTRON CYCLOTRON-RESONANCE
HEATING
HIGH-FREQUENCY DISCHARGES
HYDROGEN 1 MINUS BEAMS
ION BEAMS
MAGNETIC FIELD CONFIGURATIONS
NEUTRAL ATOM BEAM INJECTION
OPEN CONFIGURATIONS
PLASMA HEATING
PRODUCTION
RESONANCE